1. Field of the Invention
The present invention relates to a flash memory gate structure and a method of making it. In particular, the present invention is directed to a gate structure with a smaller gap disposed between the select gate structure and the floating gate structure as well as a method of making it.
2. Description of the Prior Art
A flash memory is a non-volatile memory. The information is nevertheless stored in the memory in the absence of the supply of an external power supply. In the recent years, due to the advantages of the flash memory capable of electrically re-programming and re-erasing, it has been widely used in mobile phones, in digital cameras, in video players, in personal digital assistants (PDAs), or in a system on a chip (SOC).
However, in the current process of fabricating the flash memory of split gate type, a problem of overlay shift between the select gate and the control gate often happens. Another problem is complicated steps. Accordingly, a solution is needed to improve the situations.